DE2022589B2 - Circuit for automatic chromaticity control in a color television receiver - Google Patents

Description

40 of the picture tube is significantly impaired by the undesired interfering components. Such Color representation appears in a relatively arbitrary

The invention relates to a circuit for automatic distribution over the oversaturated screen

table chrominance control in a color television tem- or undersaturated. This somehow makes one in the picture

catcher with an adjustable amplifier, which is 45 Heckige or blotchy representation. Such, through

introduction of color-frequency-frequency signal components to indicate the presence of interference

including a predetermined band of chrominance signals - representations can be displayed for the buyer or

Lich supplies the color sync signal, and be completely unreasonable with a ter.

Color synchronization signal amplifier, whose output signal from BE-PS 715 673 is a circuit arrangement

the frequency-determining member of an oscillator 50 voltage for automatic control of the chrominance signals

for its frequency and phase synchronization to- in a color television receiver with a controllable

to be led. Chrominance intensifier and a selective color synchronous

An automatic chrominance control (AFR) is known in signal amplifiers, in which the color synchronous ratio many color television receivers signal a frequency-determining part of the color spectrum. It is desirable because the oscillator is synchronized with its phase and frequency Changes and fluctuations in the signal chronization is fed.

Propagation path as well as other factors which are higher. In contrast, the object of the invention is

Frequent chrominance components of other amplitudes in the improvement of the control properties of a sol-

are exposed to fluctuations than the low-level circuit in the sense of a more complete grain

quenten information components of the signal ^{mixture 6l)} compensation of selective fluctuations in the color signal

sches. The components intended for most receivers in relation to other signal components de:

automatic gain control (AVR) is sufficient signal mixture. Here dynamic over

not enough to avoid such selective fluctuations or controls of the chrominance channel

Changes in the chrominance signal components are full and the scheme should change with regard to re

to compensate. ⁶ 5 would have the effect that on the Bilcischirn

In addition to the selective changes in color, no false color saturation occurs, which di <

Art signal components result in the further subjectively affecting color reproduction. Tue «

blem of the harmful influence of interference, the interference signal suppression should be improved in order to

5 6

the circuit should also be connected in an integrated form to terminal 115, via which the color

be trained. demodulator stages (not shown) are fed.

This task is achieved by the in claim 1 to a second output of the oscillator 14 is to a

given characteristics solved. Training the receipt of a used for the AFR scheme

Invention are set out in the subclaims. 5 peak detector 19 connected, with one

In the following, the invention is based on the external time settings connected via the terminal 102 of exemplary embodiments explained in more detail. constant circuit 20 is connected. The top-it shows detector 19 generates a peak value of the oscilloscope

F i g. 1 the block diagram of a chrominance fan signal proportional control voltage,

action circuit of a color television receiver with io A color syn-

AFR circuit arrangement according to the invention, chronsignal is via the color sync signal amplifier

2 shows a cover 11, shown partially in block form, and the clamp 111 tailored to the quartz filter 12 Circuit diagram of the circuit according to FIG. 1 led. The values in the quartz during this interval and stored information affects the amplitude and

F i g. Figure 3 is a schematic diagram of the chrominance treatment phase of the signal from oscillator 14 for the duration circuit in integrated training together with a scan line. One to the AFR time constant shell outside of the integrated circuit chip an- device 20 charges on the top-arranged circuit elements. value of the oscillator signal.

F i g. 1 shows in simplified block form the switching It is therefore, as will be explained, the Scheme of part of a color television receiver with * »perceived signal level for the AFR the Spitder AFR circuit according to the invention. A video zen value of the oscillator signal influenced by the mixed signal is an input terminal 101 of an input color sync signal and associated integrated circuit board 2 supplied. The interfering components, proportional. This true circuit of the plate 2 contains a first colored peak voltage is a direct current amplifier 10, which is supplied with 25 more amplified 21 at terminal 101, which is fed with its output to Catched signal is amplified and connected to a color synchronous chrominance preamplifier 10 to its signal amplifier 11 and a chrominance amplifier 18 to regulate gain, in such a way that the outgoing output level of the chrominance signal according to the

External recorded peak amplitude of the oscillator signal connected to terminals 116 and 114, respectively

(not contained in the integrated circuit) is selek- 30 regulated.

tive networks 4 and 9 ensure that the first The integrated circuit board 2 also has chrominance amplifier (chrominance preamplifier) 10 and the one terminal 112 for the supply of a chrominance amplifier 18 are color-selective. The color-suitable operating voltage + V _cc from a normal synchro signal amplifier 11 is in each case during the chen source 8. A ground connection 105 supplies a single horizontal synchronization interval by means of 35 common reference potential for the integrated circuit of a keyed circuit 6, the input 110 of which is a circuit board 2. The integrated circuit board. Horizontal scanning pulse is supplied, scanned. The counter 2 is also activated via a terminal or a touched circuit 6, the color sync signal connection 113 to a variable gain control amplifier 11 during the horizontal retrace and circuit 3, which will be described later, locks the chrominance amplifier 18 during this inter- 40 closed,
vails. F i g. 2 shows partly in block form the switching

The output signal of the chrominance signal scheme of an integrated circuit for the chrominance intensifier 11 is also generated outside of the signal treatment including a circuit board 2 integrated according to the invention between the AFR circuit. In Fig. 2, the central output 111 of the color synchronizing signal amplifier and 45 value detector function are carried out within the oscillator circuit at the input 107 of a color subcarrier oscillator 14; the arrangement used for this purpose, ordered narrow-band quartz filter 12 is filtered. This will be discussed in more detail later and is included in the crystal filter 12 used in the oscillator 14 in a reverse U.S. patent application Ser. 823 066 of the equilibrium coupling loop is arranged, provides described in detail to the applicant.
Terminal 108 a continuous oscillation which is in the phase 5 °. The composite television signal is fed to a connection 101 and frequency with the incoming chrominance synchronous signal, which is synchronized to the base of a first chrominance signal, if any. stronger stage with a transistor 30 with over one

The output signal of the oscillator 14 is connected to a resistor 31 with a grounded emitter.

Average value detector 15 for the color lock perception- The transistor 30 belongs to a cascode amplifier

mung supplied. The mean value detector 15 is with 55 ker, which also has a transistor 32 to the

its output via terminal 109 to an emitter connected to the collector of transistor 30

suitable time constant circuit for the AFR and ter contains the collector of transistor 32 is with

Color barrier threshold setting coupled to a terminal 116 of the integrated circuit board

The output of the middle detector 15 is linked to a chens. A parallel oscillating circuit with a

Color lock switch 17 on the integrated circuit 60 coil 34 and a capacitor 35 is between the

plate coupled to terminal 116 and one connected to terminal 112

The color lock switch 17 is connected via a terminal 104 to operating voltage sources 29 (+ V _cc ) .

to an external filter 7 to reduce the color drips.

coupling coupled. The output of the color The parallel oscillating circuit or resonance circuit has blocking switch 17 is connected to an input of the chrominance 65 a bandpass frequency characteristic, which is connected to the color amplifier 18, in order to switch off the color bit channel and part of the sideband range for black and white transmissions. An edge is used to select the bandwidth for the amplified and the output of the chrominance amplifier 18 is to a signal mixture fed to the connection 116. A to

(ρ

The preamble network associated with the AFR control loop is approximately 3 MHz. The parallel resonance circuit lies

of a follower transistor 36, the base of which is also in the feedback branch of the 3.58 MHz oscilloscope

to a reference voltage source, consisting of the lators, as will be explained.

Series connection of a resistor 37 and a loading The color sync signal isolation amplifier 27 supplies

pull or Zener diode 38, is coupled, with a 5 when keying during the horizontal interval on

Reference variable fed. conclusion 111 a reinforced version of the color synchronous

The connection point of the resistor 37 and the signal, which represents the color carrier of the Zener diode 38 used at the transmitter end, is ai the base of the follower transi-frequency and is connected for demodulation purposes bestors 36 , which is necessary with its emitter. The amplified color sync signal is a resistor 40 to the base of a bias voltage from terminal 111 of a narrow-band crystal 128 voltage follower transistor 22 is connected. The transistor 22 with a resonance frequency at the color carrier frequency is fed with its emitter to the base of the frequency (3.58MHz). The precise resonance transistor 32 connected to this with a frequency is further supplied by a variable bias voltage, and is set with its emit capacitor 129 , which is in series with the ter via an emitter resistor 23 on. Dimensions. 15 crystal 128 between the connection 111 and the connection

The transistor 32 is connected by means of a follower circuit 107 or input connection of a color carrier

device designed transistor 33, which is coupled to its oscillator.

Emitter directly to the emitter of transistor 32. The color subcarrier oscillator consists mainly of

is closed, current-controlled and amplification- an amplifier stage with transistors 126, 127 and

rain. The base of the transistor 33 is via the row 20 128 and a limiter stage with a transistor

connection of two diodes 44 and 45 on the emitter 125. The transistors 127 and 128 are in beta

ter of the transistor 36 is fed back. The diodes 44 designed multiple circuit, with their collector

and 45 are interconnected with color transmission by a zwitter and are the basis of the

see a color barrier circuit 28 and the connecting transistor 128 from the emitter of transistor 127 from

dungspunkl of these diodes with the base of the Trans 25 is controlled. The emitter of transistor 127 is connected

Sistor 33 coupled resistor 46 in the pass-further via a resistor 135 to ground. A between

line condition held. An AFR control voltage see the common collector connection and the

is the connection point of the base of the transistor operating voltage connection + V _cc switched resistor

22 and the resistor 40 via a stand 136 forms a common collector working

Collector coupled to this connection point, resistor for transistors 127 and 128.

th transistor 42 is supplied. Due to the beta multiplication

The amplified circuit appearing at the terminal 116 allows weak base currents through the chrominance signal to flow to the input of a second chrominance-base-emitter junction of the transistor 127 , amplifier 24, which is a chrominance amplifier while a relatively high gain for stage 25 and a color sync signal- Isolation amplifier 35 the transistors 127 and 128 is obtained. The Beker 27 controls. A further selectivity for the drive with a weak or low base current is achieved by an external oscillation - there is a direct current stabilization in the temperature circuit with a coil 72 and a capacitor 73 fluctuations for the oscillator as well as in the chip, which is due to resonance in the chrominance-sideband frequency changes normally beta-sensitive frequency range are matched. This resonant circuit 40 are borrowed.

70, 72 results in connection with the aforementioned. To further stabilize the oscillator, an oscillating circuit 34, 35 is the required selective band direct current negative feedback amplifier with a pass characteristic for the chrominance frequencies. The transistor 126, which has a collector with its collector over a dye type amplifier 25, has a terminal 113, an external gain control circuit for manual operation 45 is connected to the resistor 137 to the operating voltage source + V _n. The emitter of the drive with resistors 86 and 87 and a capacitor 126 is connected via the series circuit three capacitor 85 . Resistors 138,139 and 140 to ground. The same-

The chrominance output signal of the amplifier 25 current negative feedback for the oscillator is Durcr

can be removed at connection 115 and suitable one between the connection point of the cons

Demodulator circuits (not shown) fed 50 stands 138 and 139 and the base of the transistor;

will. The color sync signal separation takes place 127 coupled resistor 141 received. The Ver

by touching the color sync isolation amplification connection point of the base of the transistor 127 and de!

kers 27 by means of a keyed circuit 26, the resistor 141 is connected to a terminal 107

by a horizon fed to the connection 110 , which is used as an input connection for completion

key pulse is activated. The in the key circuit 55 completion of the AC feedback branch de:

26 treated key pulse is also used for the chrominance oscillator.

stronger 25 fed to the color sync signal from Because of the feedback ratio and de:

the signals fed to the demodulator to remove the large open loop gain of the amplifier:

femen, ensures the circuit arrangement described above

At the burst signal isolating amplifier 27, 60 voltage is a low input impedance for the oscil

via the feedback output connection 111 a generator circuit at connection 107. Due to the:

external frequency-selective load element, consisting of low impedance, the resonance circuit with the

from the parallel connection of a coil 98, a resistor quartz 128 and the capacitor 129 proportionally

stand 99 and a capacitor 120 connected. frequency-independent of the properties of the ver

The transistors used between the operating voltage source + V _cc and 65 work,

The parallel resonance circuit coupled to the terminal 111. The transistor 126 is connected to its collector

is dimensioned so that it has a fairly wide frequency - the current limiting resistor 137 at + V _cc

permeability on both sides of a center frequency of closed. The emitter of transistor 126 is fer

ner activated 125 Toggle line interval to the base of the limiting transistor, and during the re-closed, which belongs to the oscillator circuit and extraction of the burst signal which is approximately an additional phase shift to retrace occurs during, blanked. For the re-180 ° supplies for the arrangement to swing. The acquisition and suppression of the color synchronous transistor 125 also fulfills, as mentioned above, 5 signals to the terminal 110 and from there the mean value detector function, while an adjustable keyed circuit 26 a horizontal key pulse supplying ftC emitter element leads the color block and AFR. During the horizontal interval, the threshold setting activated worried. keyed circuit 26 the color sync signal separator

The collector of transistor 125 is connected via an amplifier 27 and blocks the Farbartverstärker 25, current limiting resistor 142 to the terminal io appear therefore Farbsynchronsignalfrequen- 111 is connected. The emitter of the transistor 125 is zen, connected to the plate through the coil 98, the resistor 99 and the bandwidth connected to the terminal 109 on the integrated circuit capacitor 120. The outer adjustable connector 111.

/? C element for the AFR and color lock threshold. The resonant circuit just mentioned is also used

Value setting is coupled between terminals 109 and 15 to remove the line retrace pulse frequencies and consists of a resistor 146 that is changed so that you cannot influence the color sync output signal and a variable resistor. The amplified color synchronizing capacitor 145. The emitter of the transistor 125 signal is fed through the crystal filter with the crystal 128 is also connected to the input of the color barrier switch and the tuning capacitor 129 to the oscillator 28 to the input terminal 107 of the chrominance amplifier 25 . The oscillator is to be switched off for black and white transmission and, as already mentioned, is input-synchronized (injection color transmission the diodes 44 and 45 are synchronized via the) and therefore supplies a signal at its output resistor 46 with forward bias current to be supplied (terminal 108) with the reinforced supply. Synchronized color sync signal at terminal 111

In the emitter circuit of the transistor 126 of the color oscilloscope 25 is.

A control signal for the AFR is thereby generated. An important property of the input-synchronous

hold that the junction of the resistorsized oscillator is its ability to properly respond to the color 139 and 140 to the base of an AFR detector sync signal. When the oscillator circuit is connected to the transistor 155 which is used for the purpose, the oscillator will be. The emitter of transistor 155 is connected to the quiescent signal at the emitter of transistor 126 through inclusion 102 on the integrated circuit board of resistor 146, which controls the oscillation. amplitude limited to a first level (1 to

An outer time constant network for the AFR V · volts peak-peak) is set. When the transi mode, consisting of the parallel connection of a disturbing 127, a color sync signal with a voltage resistor 156 and a capacitor 157, 35 of 3 volts peak-to-peak is coupled via the quartz 128 at the connection between the terminal 102 and ground. Terminal 111 is fed, the oscillator signal rises. The collector of transistor 155 is via a current limiting resistor 158 at the emitter of transistor 126 to approximately 4VoIt, which increases this transi- peak-peak. This size of the Amplitudeändestor against overcurrent in the event of accidental occurrence (almost three times) enables the wrong voltages to be protected at connection 102 , to operate reliably at 40 color blocking circuit 28 and to connect the operating voltage. also the amplifier belonging to the oscillator in

The AFR control loop is operated by a transistor in its linear dynamic operating range. 42 closed, the base of which is connected to the emitter It is therefore the amplitude of the oscillator

of transistor 155 is connected. The collector supply during the presence of the color sync transistor 42 is a function of the same at the connection point between signals. The oscillator voltage generated at the connection of the base of the transistor 22 and the bias circuit of the first chrominance amplifier stage appearing at the connection point of the resistors 139 and 140 also represents the associated resistor 40 connected. Peak amplitude of the oscillator signal as it is

The method of operation of the chromaticity treatment is now to be determined by the prefiltered signal coupling via the control switch with the AFR circuit, which is described 50 relatively narrow-band quartz 128 . The signal applied to terminal 101 is. As mentioned, the amplitude of the oscillator mixture depends in the cascode circuit of the transit signal mainly from the color sync signal, if interfering 30 and 32 are amplified and because of the Q value it is present, and can be over a range of the resonance circuit with the coil 34 and the Con- 3 to 1 fluctuate.

Capacitor 35 limited to a predetermined bandwidth at 55 Any interference signals with frequency component connection 116 that may be present. The amplified signal nenten within the pass band of the crystal is then from terminal 116 to the chrominance amplifier 128 can be coupled through during the chrominance signal interval 24 and from there to the chrominance amplifier 25 and the also so that they are fed to the am-chrominance signal isolation amplifier 27. amplitude of the oscillator signal depending on the frequency and as is known, the chrominance channel will preferably influence the phase in a similar way as the color end of the color sync signal interval is blanked out to synchronize signal. The transistor 155 connected to its emitter to prevent the downstream demodula circuit 102 from working in gates due to the coupling of the color synchronous connection with the resistor 156 and the dsm consignal generating foreign or interference products. capacitor 137, which is between the terminal 102 and

Methods to achieve this are known and are 65 mass coupled, called a peak detector,
are usually used as color sync signal suppression. The voltage generated on capacitor 157 is there

kung or blanking. The chrominance amplification- the peak amplitude of the oscillator signal at the amplifier are preferably during the main part of the connection point between the resistors 139 and

11 12

140 and the base of transistor 155 again. The stors 32 are lowered by a factor of Vs and flow

The time constant of the AC element 156, 157 is sufficient to ensure the same currents through the transistors 32 and 33.

around the peak amplitude of the demodulated oscillator- If the emitter voltage of transistor 155 is un-

gate signal over an entire grid at the beginning, which is approximately equal to 1 volt, results in the full AFR effect

Keep line. Due to the interfering signal coupling over 5 kung, corresponding minimal amplification of the trans-

the crystal filter 128 can therefore be the capacitor 157 sistor 32.

on the peak value of the oscillator signal, controlled In the case of a weak signal mixture, the

due to any interference impulses and the color - a bad signal-to-noise ratio (signal-to-noise ratio)

Sync signal, to be charged. corresponds, the chrominance channel can be

The positive voltage element of the stronger interfering components generated in this way on the capacitor 157 is throttled voltage reaches the base of transistor 42, which is with be. This leads to an oversaturation of the image creators Collector at the connection point of the re-representation prevented by ensuring that stand 40 and the base of the follower stage 22 change the dynamic range of the chrominance demodulators is closed. When transistor 42 is conductive, less or the color picture tube or the downstream one Base current available for transistor 22, whereby 15 chrominance amplifier stages, e.g. B. 24 and 25, not mostly the current conduction of the transistor 32 is increased.

decreases and the gain is reduced as a result The overall effect of the AFR circuit is on addition to giving the viewer a color representation

The replay connected to the connection 109 is shown, the less with weak interfering signals Status 146 determines the maximum peak-peak-20 saturated, but more appealing and pleasant. Voltage that the oscillator can easily process under relatively good received signals can. Adjusting the resistor 146 increases the amplitude of the oscillator signal hence the one at the junction of the objectionable on the amplitude of the color sync signal would be 139 and 140 available peak-to-peak ampli-dependent, so that the voltage on capacitor 157 tude definitely. At the capacitor 157, a predetermined value is determined by fluctuations in the color synchronization signal ampli DC voltage is determined on the basis of the quiescent rate. By doing a peak demodulation oscillation amplitude generated by the oscillator, whose amplitude corresponds to the amplitude of the signal of the color subcarrier oscillator, Size influenced by the setting of the resistor 146 by interference and the color is synchronized is. In the absence of the color sync signal that takes place, the interference becomes after passing through through this voltage the transistor 42 block 3 ° and color sync signal components through the tense. narrow-band quartz filters effectively reduce the influence of the

With increasing peak-to-peak amplitude of the oscilloscope interference on the amplitude of the color sync signal

generator signal due to interfering signal coupling measured during the horizontal line,

the narrow-band quartz or due to the

the presence of the color sync signal, the relationship between the interference amplitude and the total

capacitor 157 to the peak value of the amplitude amplitude of the chrominance oscillator signal

larger signal. When the voltage on the right increases, a control voltage is obtained

Capacitor 157 begins to conduct transistor 42, which is the color affected by the interference

so that base current is derived from transistor 22, synchronous signal amplitude is proportional.

namely via the collector-emitter path of the 4 ° Another feature of the described arrangement

Transistor 42 and resistor 43 to ground. The reason for this is that if there is excessive interference

The voltage at the base of the transistor 22 drops, the chrominance signal gain is reduced and consequently, like the emitter voltage, it drops, as a result of which the color barrier is protected in its operation. Whether, in turn, the bias and gain of the color barrier circuit 28 as the mean value transistor 32 is lowered. Who works with his emitter 45 detector, it is in practice somewhat more troublesome when connected to the emitter of transistor 32. It can therefore happen that with a large transistor 33 a base _{bias voltage which is lower by interference signal amplitudes during a black and white 2 V 1} ,,, than the emitter voltage of the transit transmission, the color blocking circuit 28 receives the color gate 36. This voltage drop by 2 V ₁ , ,. is falsely activated by artkanal. However, this is generated by the diodes 44 and 45, which are largely prevented by the resistor tor connected to the 50 by the AFR-Detek color barrier circuit 28 being biased into the conductive state in the presence of strong interfering signals. Chrominance gain downregulated.

The voltage at the base of transistor 32 is Tn F i g. 3 is a complete integrated scarf Because of the voltage drop across the base-emitter exceeds tung arrangement shown with the above described AFC transition of the transistor 22 to _be about 1 V lower 55 circuit, further wherein the g i in F. 2 in as the voltage at the emitter of transistor 36. The circuit shown in block form for the color barrier-emitter voltage of transistor 32 and consequently the stronger and the color barrier circuit in individual transistor 33 is therefore 2 V ,, _e below the reference is shown.

voltage at the emitter of transistor 36. As a result, the amplified chrominance signal arrives from the terminal ensures that transistor 33 is initially ⁶ ° 116 via Zener diode 51 in series with the reverse blocking or blocking voltage. stood 52 at the base of a follower transistor 50. The

When the chrominance signal rises from zero, the control and bias circuit for transistor 50 begins to conduct, so that the base voltage drops through a resistor 53 connected between its base and ground State, while the tran- ⁶ 5 emitter follower switched transistor 50 is biased with its sistor 33 in the forward direction. When the collector at terminal 112 (+ V ") and with its voltage drop at resistor 40 is approximately equal to the emitter across the series circuit of the working 1 V _be , the gain of the transistor 56 and 57 has been connected to ground.

13 ^ 14

The transistor 50 controls a chrominance amplifier - the + ^ "- line and with its emitter directly ai

transistor 60 and a burst signal amplifier- the base of transistor 68 is connected. Hurry

transistor 61 aui .. The base of transistor 60 is connected to resistor 92 between the emitter of the transistor

the connection point between the emitter of the stors 91 and the base of the transistor 66 is connected Transistor 50 and resistor 56 connected to 5 A reference voltage for the base of transistor 6 (

sen, and the base of the transistor 61 is connected to the ver is through the between the base of this transistor

connection point of resistors 56 and 57 and ground coupled Zener diode 73 supplied,

closed. The emitter of transistor 60 is through the burst signal amplifier transistor 61 is

a negative feedback resistor 62 to the emitter with its collector via a current limiter

of transistor 61 coupled. The connection point io withstood 95 with the connection point of the emit

between the resistor 62 and the emitter of the ter another differential amplifier stage with Tran

Transistor 61 is connected to terminal 103 on transistor 96 and 97. The basis of the Transi

integrated circuit board connected. Zwistors 96 is pretensioned by being attached to the

see the terminal 103 and ground is an external connection point of the resistor 92 and dei

ÄC parallel member with a resistor 63 and a 15 cathode of the Zener diode 93 is connected. Dei

Capacitor 64 switched. The collector of transistor 96 is directly connected to dei

The transistor 60 has its collector connected to the + K _{r £} . Line.

Connection point of the emitter of two transistors The transistor 97 has its collector at the

65 and 66, which lead to a switchable differential stage. Terminal 111 of the integrated circuit board? hear connected. The collector of transistor 20 is connected. The outer parallel resonance circle mil

66 is at the junction of the emitter of two of the Spuk 98, the resistor 99 and the capacitor connected as a differential amplifier transistors. The transistor 68 has a frequency response of around 3 MHz, and its collector is connected to a terminal 112. see the terminal 111 and the operating voltage The transistor 67 is connected with its collector via a 25 source + V _cc . The resonance circuit belongs to the Zener diode 70 connected to the base of the transistor 69 for separating and output switching. tion.

The connection point between the anode of a keyed transistor 121 is

Zener diode 70 and the base of transistor 69 is lektor to the +! '"- line (terminal 112) and with

via a resistor 71 to ground (reference potential). 30 its emitter via the series connection of two

The connection point between the collector of resistors 122 and 123 is connected to ground.

Transistor 67 and the cathode of Zener diode 70 The junction of resistors 122 and 123

is connected to a terminal 114. An outer one is attached to the bases of transistors 65 and 97.

Parallel resonance circuit with a coil 72 and one closed. The base of the transistor 121 is directly connected to

Capacitor 73 is connected to terminal 110 between terminal 114 of FIG. In operation is the

integrated circuit and the operating voltage connection 110 a horizontal pulse positive

source + V _cc switched. This is fed to chrominance frequencies polarity, as will be described later

responsive selective network provides another will.

Amplification of the base of transistor 60 trains- The oscillator, as in connection with Fig. 2

led chrominance signals. 40 described has one attached to the base of the transistor

For the controllable bias of the transistor 67, 127 is connected input terminal 107 and one

one with its emitter to the base of the transistor output terminal 111. The one in series with the output

67 connected follower transistor 75 is provided. Vocal capacitor 129 lying quartz 128 is between The emitter of the transistor 75 is connected to the terminals 107 and 111 and bil-resistor 76 a part of the frequency-determining network is attached to the base of the transistor 66 closed. The base of the transistor 65 is via the color synchronous series circuit that is selective for the oscillator and the selective color synchronous series two diodes 77 and 78 with the signal filter element. With the Quartz 128 and the Kon-Basis of transistor 66 coupled. The base of the capacitor 129 are the coil 130 and the capacitor transistor 75 is connected to terminal 113 to neutralize the capacitance of the quartz sensor, to which an external voltage divider 5 ° housing is also connected in parallel. Between the connection with resistors 86 and 87 is connected. 107 and ground a capacitor 132 is connected,

The series connection of resistors 86 and 87 that stabilizes the feedback amplifier by

the high-frequency wild oscillations of the oscillator with their connection point to the connection

113 are connected is between the operating. prevented.

Voltage source + V _ec and ground switched. The 55 As previously described, the emitter of the Tran resistors 86 and 87 are dimensioned so that the transistor 125 is connected to the terminal 109 on the integrating temperature synchronization with the circuit board thru the resistors. An externally adjustable voltage divider for referencing the base of the AC element for the AFR and color barrier threshold bias follower transistor 91 is produced between the 94 and 100 terminal 109 and ground. A decoupling capacitor 85 is connected between the value setting with the variable capacitor connection 113 and ground. A ground return path for tet. The emitter of the transistor 125 is connected to the base of the transistor 75 is connected through a resistor of a follower transistor 147 in the color barrier switching station 89 in series with the collector-emitter path device. The emitter of the transistor 147 of a transistor 65 belonging to the color barrier circuit is connected to ground via a resistor 148 and is given at 90. also via a resistor 150 to the base

The bias for transistor 68 is connected by a follower transistor 149.

Transistor 91, which has its collector connected to the connection point between the base of the

Transistor 149 and resistor 150 are connected to terminal 104 on the integrated circuit die connected to which a filter capacitor 151 connected to its other assignment to ground Ground dissipation of high frequency signals and to define the time constant of the color blocking circuit connected. The emitter of the transistor 149 is connected to ground and via a resistor 152 is connected to the base of the transistor 47 via a resistor 153.

The transistor 47, which is designed as an emitter amplifier circuit and belongs to the color lock switch, is with its collector is connected via the resistor 46 to the diodes 44 and 45 to this with a to supply forward voltage bias current. The collector of transistor 47 is also connected to the base of transistor 90, which is the output stage of the color lock switch to operate the color lock forms connected.

As in connection with F i g. 2, the control signal for the AFR is obtained by that the connection point of the resistors 139 and 140 in the emitter circuit of the transistor 126 of the color oscillator is connected to the base of the peak detector transistor 155.

The aim now is to examine the mode of operation of the integrated circuit with particular reference to those in F i g. 3 contained circuit elements which are shown in FIG. 1 and 2 are not specifically illustrated will.

The composite signal fed to the connection 101 is in the cascode circuit with the transistors 30 and 32 amplified and due to the Q value of the resonance circuit with the coil 34 and the capacitor 35 limited to a predetermined bandwidth at port 116. The amplified signal arrives Via the Zener diode 51 and the resistor 52 to the base of the transistor 50. This coupling via the Terminal 116 to the base of transistor 50 is particularly interesting in that it is used of the Zener diode 51 connections on the integrated circuit board can be saved.

In arrangements with discrete circuit elements, the coupling between transistor amplifier stages with an inductance as part of a collector load with the help of a capacitor that is the collector of the Coupling the preliminary stage with the base of the downstream stage, or with the help of a transformer with primary and secondary winding. In both cases, the collector DC voltage is not taken into account and obtain the AC signal swing.

These types of coupling are impractical for integrated circuits, since there are at least two for both types Connections on the integrated circuit die are needed to connect the integrated transistors with to connect the coil and the capacitor, which must be arranged outside of the plate, wherein the connection of these components to the base of the downstream stage via the second connection he follows.

One known solution in the case of integrated circuits is that a coupling resistor, which is connected to the collector of the selective amplifier, is provided on the integrated circuit board. The + K _cc connection of the integrated circuit supplies information which can regulate the direct current transmission of the signal from the resonant circuit connection. Because of the coil, the resonant circuit connection (ie the collector electrode) carries a direct voltage which is essentially equal to the magnitude of the operating voltage + V _cc . In known arrangements, the resistor is connected between the collector terminal 116 and the base of the downstream stage. The connection point between the resistor and the base of the downstream stage is connected to a constant current source,

ίο the one with a transistor whose base with a reference voltage is acted upon, can work.

In this way, the voltage drop across the coupling resistor is essentially a fixed direct voltage, so that alternating voltage signals are translated from one direct voltage, namely -t- V _cc , into a second, fixed direct voltage which is considerably lower than + V _cc. This method has at least the following disadvantages: The bandwidth of the circuit is now limited if a small constant current source and high +! ^, .- voltages are necessary because the coupling resistor controls the Miller capacitances of the downstream stage and any collector capacitance of the current source.
A more serious problem arises from the following:

The selective amplifier stage, like transistor 32, with an inductive output _{load can have voltage amplitudes above the + F cc} operating voltage. When using an integrated coupling resistor, the "well" containing the resistor in the substrate or plate must be biased to a voltage above B + in order to prevent the resistor from being forward-biased and acting as a diode. A "well" is a zone of specific doping provided in the integrated circuit substrate or lamina, which is adapted to integrated circuit elements. Wells can contain dopant concentrations that make them suitable for transistors, diodes, or resistors. In order to provide such a voltage on the integrated circuit die, an additional connection is required.

Another solution would be to bias the tub by passing the resistor through it, whereby the capacitance between the well and the substrate is added to the self-capacitance of the coil will. The well-substrate capacitance has a relatively low g-value at high frequencies and is non-linear at all frequencies. In any case, the Coupling resistor on an integrated circuit chip an area of considerable size on the Platelets to compensate for these adverse effects.

In FIG. 3, on the other hand, a Zener or avalanche diode 51 is used. The diode 51 is formed by a pn junction which is produced in one and the same diffusion step together with the base-emitter junctions of the monolithic transistors. These diodes can now be contained in a + V _CI biased tub which contains most of the integrated resistors of the integrated circuit arrangement. The voltage at the n- or cathode connection of such a diode can swing out by the value of the avalanche voltage, which is 6 to 9 VoI, above + V _cc without losing the insulating properties of the component

409 538/15.

It is largely prevented that foreign- the color sync ^ onsjnal rmt ^ never ^ ^^ _β SlätinTen oscillating circuit, tude ^ J ^ ServaUs introduced distortion

B ^ AnorQ ^ ungnlchFig-SkanndieLawine ^ - ^ VwegS through the resistor 56igeg or Zener diode 51 together with the resistor "^ mWZ ^ _{the base of the} transistor 60

52 are used to amplitudes of the collector 5 ^be ^ ° ^ _will allow the chrominance channel during the gate voltage of the transistor 32 above + V » _Fa ^B _h ^e ^^ _igna linte ^ lls preferably blanked, while at the same time a ratio ^^ ™ Jk that the demodulator ^ due to a moderately constant bias voltage (direct voltage) for around g ^ ™ ^ of _the color sync signal foreign prod transistor 50 is maintained. . η, VteSugen methods for this are known and

The so biased transistor 50 is referred to as emitter xo domestic product ^ "fj, ^ ^ ₅ Farbsynchronsignalunterdrukfolger with divided or split emitter load for ^w ^ f ° f ™ keying. The Farbartver-Aussteuern the Farbartverstärkerstufe 60 and the effect or" s _Wanren d of the main part of the FiCcSronsYgnaleamplkterstufe 61. The ^^^ dStot and during the re-Aiupümde of the base of the F ^ ^ers i ^ark f **?, ^ Γ ₈ ^ s color sync signal, which during the supplied signal is slightly larger than the ampli -. ₅ wmnung oe J blanked

tude of the base of the Farbsynchronsignalverstarkers ^ «Xsern purpose, during the period of to-61 supplied signal, since the base of Farbartver- ^ J ^ ^ _n part sync oscillation Zugen stärkers 60 directly zwtschen to the junction ^ _^™ 6Ι ™ Γ £ η shoulder of the Honzontalsynchromdem emitter of the transistor 50 and the resistor ^^^ line back pulse of the base of the 56 and the base of the transistor 61 to the conn- ~ ^ f ^ f ^ ^ led to the following Vordungspunkt of the resistors 56 and 57 connected os- Trraistors ^ "* _{d of the itive} impulse is sen lind. This arrangement results in the following processes from tost. ^ _{so that the other}

share and work in the following way: Jer TransuWr ^ _ardent FaAsynchron-

The standards for color television transmission are the basis of ^ ran _{orea 61 and 97 in} connection

so that the amplitude of the chrominance signal corresponds to the ampli- »5 signal ^ urch *« consisting of the par-

tude of the color sync signal The dung only the K ^ _9g> condensate

Amplifiers for these signals have to be able to m * _η ά the damping resistor 99, selelu.v the maximum amplitude of the signal in question tor UX »uno _{The amplified} color synchronous

to process without distortion. This is based on fol- stvarU ^ who ^ ^^ _m

in the following way:. ³ ° '^ resonance circuit is also removed from the

^g The DC voltage drop across the emitter resistor D «^ signal components with the

62 in series with the emitter of the chromatic amplifier AiBgang ^ gna ^ g Simultaneously becomes during

60 is approximately equal to the DC voltage ^{drop at the, u} ™ ^m ^ _{hronä gna} lintervalls, the voltage across the resistor 56 in series with the emitter of the transistor 65 is positive. The base voltage sistors 50. The resistance 62 causes a current 35 Bas "^ ^it _{surplu 65} hreitet the base voltage

Negative coupling for the chrominance amplifier stage 60 ° "™ ^1S _{point of the} transistor 66 weger.der rw, -during both stage 60 and stage 61 to ^^ { _of transistors 65 and 66 gcko a common ground return path over the shear base ^ ^ _{at least 2 v}

Terminal 103 and resistor 63 have. peiten u ou also limit the amph

The DC voltage at terminal 103 is because of ₄ o J ^^ JS « _on | _he base of the transistor bridging by the capacitor 64 dissipates the as V _{def coli} ect orvoltage

relatively constant. However, the base of the tran- 9 £ is about an _emittance j «

sisitors 61 to a point of lower tension an- äPmlrtuae z ^ _{as dic des Tr s} t _{ors 66}

coupled as the base of transistor 60. The two transistors W ensure that the transistor

Levels 60 and 61 are therefore proportionally the 45 positive Uadu ^ ^ _Emitte " _pan " _U ng um

biased same level while they further only stonrogePj ^ ^ _{Basisspannu "g HEG} t.

an external output terminal (port 103) up jundestens, _Le itungsweg for the chromaticity

point. Therefore, the amplifying ends 60 and B »defeat ^{α of} _{the transistor} 60 to

61 a common input and a common signal from no chrominance channel during

Emitterstromweg seeds, so that a common arrival 50 g of ¹ ^ ⁴ i ^^ _{Ansch USS} 110 supplied posschluß 103 for the outer bias voltage used ^ "^^^ fimpulses locked or abgeschal-

^We furthermore ^a degree of signal attenuation may tetfct. . _{the saddle} i _tU ng regardless of the comparison D e Arbertswe _absentia during Zeider Farbartverstärkerstufe integral of the rows strengthening Farbsynchronsignalverstarkers einge- 55 ^{len lau} ^ ^ ^{s 1S} _! r _ha t _the result that the transistor wlrden St, while both stages bias voltage of the transistor to be kept constant ^^^% ^ S _d based It can therefore _Dei Farbartverstärker _is locked J21 u _{acted 1 &} 60 due to the resistance is determined by the? J _{a r} ™ 97 therefore effected as a result of the positive Originated signal attenuation at 62 emitter Jamistor V7 we _Stromlek ung Transigrößere the amplitudes of the chrominance signals without distortion 60 terspajmung a «^ processed _{by the Transistor9} l tion, while the transistor 61, the NIE _d ^ ^re ^ _d" ^r ^, ⁵ J _{2 and the} zener diode 93 provided of the amplitude color sync signals without distortion ^ iderstanc. ^ ^^ ^ ^ ^^

tion with greater gain can process_ _k ^P _unßSW e _g to the terminal Hl for the base of the Tran

With this simple pretensioning arrangement, kungswe | works mM _Farbartigna i _e . the chrominance amplifier linear for the chrominance signals 6 ₅ «stors ^ zugetotete 8. _{stor 65 d} .

while the burst signal amplifier at its ^ enMJ is ^ ua ^^ ^.

Bias voltage because of the lack of a signal decrease its Ba ^ ι eftekti _Tr ^B _{ansistor 66 practice}

chung these chrominance signals was distorted, but because of the emitter

read the same bias network as for the transistor capacitor 129. The input impedance of the positive bias voltage supplied to the positive voltage ker at the base of the transistor 127 is due to the development. The very low AC feedback ratio of the base of transistor 60 is passed through the transistors (approximately 50 ohms). The amplifier has therefore very much amplified SO and 66 and control the transistors 67 5 little influence on the operating frequency and the damping 68 at their common emitter connection. functional properties of the circuit.
The transistor 127 amplifies the transistor amplifier 114 and from there via the Zener 128 whose degree of amplification is determined by the Koldiode 70, which works in the same way as the editor load resistor 136. The tran diode 51, connected to the base of the follower transistor 69, sistors 127 and 128 form a beta-multiplication, so that the base current at the terminal 115 connected to the emitter of the multiplying amplifier for operation with low transistor 69 is amplified, so that the DC voltage at the oscillator chrominance signals for the feed line to the demodulator output 108 is largely beta-independent. This circuit (not shown) are available. independent voltage level serves as reference equal

The Kollektui of the burst signal amplifier 15 voltage for the with the emitter of the transistor

97 is connected to the collector of the connection 109 connected to the color oscillator switch 125.

Device associated transistor 125 is turned on. The parallel resonance circuit with the coil 98, the

The oscillator circuit consists essentially of a resistor 99 and the capacitor 120 is so loaded

An amplifier stage, a limiter stage and a FiI- measure that its resonance frequency is approximately

network. The amplifier stage is through the tran- 20 3.0 MHz and c "i is the required band-

sistors 126, 127 and 128 as well as resistors 136, width and the required phase response for the color

138, 139, 140 and 141 formed. The amplifier is a syncronized oscillator resulting in

through the between the emitter of transistor 126. The oscillator is an input or external synchronizer

and the base of transistor 127 coupled reverse oscillator so that it has an output signal He-

coupling resistor 141 DC stabilized. On 25 fert, the one with the amplified color sync signal,

The reason for this direct current feedback can be the one that appears at terminal 111 and the oscillator

The oscillator is largely independent of the operating voltage via the crystal 128 and the capacitor 129

voltage and temperature fluctuations. is supplied, is synchronized.

The limiter stage contains the transistor 125 and an important feature of an externally synchronized one

the external RC 3 ° oscillator connected to terminal 109 is its ability to correctly respond to the

Link 146,145. led burst to address. With this one

In the oscillator circuit mainly described by the quartz 128, the oscillator-specific operating frequency of the oscillator is bridged The usual emitter limit of the oscillations is set to an amperage for small signals in order to ensure the oscillation start amplitude of approximately 1 to V ₂ volts peak-to-peak. The con is set by signal increases.

capacitor 145 is charged and the DC voltage rises

voltage at the emitter of transistor 125, so that the crystal 128 at terminal 111 supplied color syn-

ser is tensioned in the blocking direction. With an increasing 4 ° chronsignal from 3 volts peak-peak the signal on

Emitter voltage takes the tran-emitter gain of transistor 126 to approximately 4.0 volts

sistors 125 too. The transistor 125 of the peak-to-peak limiter stage is enlarged. This amplitude magnification

therefore has a limiting effect when the oscillator signal enables (i.e. nearly three times) a value

reaches a predetermined level. This level, the reliable working of the color lock circuit as well

for its part you peak-to-peak amplitude of the oscillator - 45 also a working of that belonging to the oscillator

output signal is reproduced in its linear dynamic range with the aid of the control amplifier.

Resistance 146 set. The amplitude of the oscillator oscillation during

The capacitor 145 is dimensioned so that the presence of the burst signal depends on

Time constant of resistor 146 and the condenser from this. The color barrier detector function will

sators 145 in the order of one to several 50 through the trans-

reren periods of the oscillator signal. That the sistor 125 in connection with the resistor 146

Output of the limiter stage at terminal 111 with and the capacitor 145 met. The way of working

the input of the amplifier at connection 107 to the color blocking circuit is as follows:

As mentioned, in the case of color transmissions, the am-

resonance circuit, which is three times greater than the oscillation amplitude of the oscillator signal

self-current feedback with such phase and amplitude as in black and white transmission. Due to the largest

tude causes the arrangement to vibrate. The circle ßere DC voltage, which in color transmission on

contains the coil 98, the capacitor 120 and the capacitor 145 is generated, the transistor becomes

Resistor 99 in the collector circuit of transistor 125.147 forward-biased, which in turn controls the transistor

The quartz 128 in series with the variable con- ^6o 149 through the resistor 150 forward-bias. One

capacitor 129 mainly determines the precise further filtering of the color subcarrier frequency is carried out by

Resonance frequency, these two elements in the resistor 150 and the capacitor 151.

Series connected between the terminals 111 and 107- The capacitor 151 results in a greater time con-

are tet. constant for integrating DC voltage fluctuations

The high Q crystal 128 is dimensioned 65 kings at terminal 109. The collector voltage of the

that its resonance frequency close to the color carrier transistor 47 is therefore relatively low, so

frequency lies. The exact setting of the resonance - that the transistor 90 in the presence of the color syn-

frequency is carried out with the help of the variable concret signal.

If how ζ. B. in black and white reception, no color sync signal is present, the voltage on the capacitor 151 is no longer sufficient to turn on the transistor 47 via the transistor 149 , so that consequently the transistor 90 goes into saturation. This has the consequence that by blocking the transistors 75 and 67, the chrominance amplifier stage is switched off. The transistors 90 and 47 function as color lock switches to ensure reliable operation in the presence or absence of the color sync signal.

As mentioned, the color blocking circuit is relatively insensitive to interference, since the mean value detector with the base-emitter junction of the transistor 125, the resistor 146 and the capacitor 145 averages out any arbitrary amplitude fluctuations in the oscillator signal due to interference with further bandwidth limitation through the quartz filter 128. Such arbitrary disturbance fluctuations are therefore also averaged away to zero at the capacitor 151. This insensitivity to interference ensures that the color barrier works reliably.

In addition, one is of the color barrier detector circuit just described a separate AFR control loop is provided, which is based on FIG. 2 explained Way works.

The tables below only contain, for example, ratings for various circuit elements the arrangement according to FIG. 2 and 3 on the integrated circuit board as well as outside given the same.

Table A.
Circuit elements on the circuit board

Resistors 23 5 000 ohms

Resistors 31 1 500 ohms

Resistors 37 5,000 ohms

Resistors 40 5 000 ohms

Resistors 43 2,000 ohms

Resistors 46 5,000 ohms

Resistors 52 1,800 ohms

Resistors 53 8 200 ohms

Resistors 56 500 ohms

Resistors 57 5 000 ohms

Resistors 62 100 ohms

Resistors 71 10,000 ohms

Resistors 76 5,000 ohms

Resistors 89 4,000 ohms

Resistors 92 5,000 ohms

Resistors 94 9 000 ohms

Resistors 95 50 ohms

Resistors 100 2000 ohms

Resistors 122 400 ohms

Resistors 123 4,000 ohms

Resistors 135 5,000 ohms

Resistors 136 5,000 ohms

Resistors 137 400 ohms

Resistors 138 820 ohms

Resistors 139 270 ohms

Resistors 140 1,000 ohms

Resistors 141 820 ohms

Resistors 142 500 ohms

Resistors 148 5,000 ohms

Resistors 150 5,000 ohms

Resistors 152 1 300 ohms

Resistors 153 1,000 ohms

Resistors 158 500 ohms

Table B.
Circuit elements outside the plate

Capacitors 35 .
Capacitors 64 .
Capacitors 73 .
Capacitors 85 .
Capacitors 120
Capacitors 129

Capacitors 131
Capacitors 132
Capacitors 145

Capacitors 151
Capacitors 157
Resistors 63 ...
Resistors 86 ...

6OpF 0.05 μ ¥ 7OpF 0.01 μΡ 75 pF 5 to 20 pF

(variable) 8.2 pF 30pF 5 to 15 pF

(changeable) 100 μΡ 100 μΡ 270 ohms 200 ohms

Resistors 87 Q-10 K ohms

(changeable)

Resistors 99 1,000 ohms

Resistors 146 0 to 40 kilo ohms

(changeable)

Resistors 156 18 000 ohms

Coils 34 with C 35 resonance frequency

at about 3.08 MHz

Coils 72 with C 73 resonance frequency

at about 4.08 MHz

Coils 98 with C 120 resonance frequency

at about 3.0 MHz

Coils 130 coupled to coil 98

Crystal 128 3.58 MHz

A Q damping resistor of 10,000 ohms can be connected in parallel with C 34 and L 35 , while a resistance of 2400 ohms can be connected via C 73 and L 72.

The circuit component values given above are representative of a monolithic chrominance handling integrated circuit having transistors that can vary in beta from 40 to 200 times. Typical tolerances for the monolithic Zener diodes are ± 0.25 volts. The resistance elements on the circuit ^{board specified above can have absolute value fluctuations of ± 25%, while the ratios between the resistances can fluctuate tan nor ± 3 β} / ο. With such tolerances, the circuit works in the specified manner with a +! ^ «- voltage of nominally 11.2 volts

For this purpose 3 sheets of drawings

Claims (10)

Patent claims: 1. Circuit for automatic chromaticity control in a color television receiver with a brisk! -; able amplifier, which when supplying signal components with a frequency of color types a predetermined Supplies band of chrominance signals including the burst signal, and with a burst signal amplifier, whose output signal is fed to the frequency-determining element of an oscillator for its frequency and phase synchronization is, characterized in that the frequency-determining member as a filter network (12) is fed back from the output of the oscillator (14) to its input, in such a way that that due to the other signal frequencies fed to its input in addition to the burst signal including spurious components within the passband of the filter network the output signal in its amplitude corresponds to the amplitude of the filtered signal frequency components follows and that the variable-amplitude oscillator signal of a detector circuit (19) for generation a control voltage is supplied. whose size is the highest peak amplitude of the Oscillator signal including any peaks generated by the spurious components proportionally and is fed to the amplifier via a coupling arrangement (21). 2. A circuit according to claim 1, characterized in that the detector circuit has a transistor (155), the base of which is supplied with the output signal of the oscillator (14), an RC circuit (156, 157) coupling the emitter of the transistor to a reference potential point. , the time constant of which, taking into account the base-emitter transition of the transistor, is dimensioned such that the detector operates as a peak detector and contains an arrangement (158) coupled to the collector of the transistor for supplying an operating voltage. 3. A circuit according to claim 1 or 2, characterized in that the filter network (12) has a has a relatively narrow-band frequency response, such that the signal frequencies including Interference components are allowed to pass around the color subcarrier frequency. 4. A circuit according to claim 3, characterized in that the filter network (12) is a quartz (128) with a center frequency close to the color subcarrier frequency and one in series with it Variable capacitor (129) for setting the exact center frequency of the filter to the color subcarrier frequency included. 5. Circuit according to one of the preceding claims, characterized in that the controllable Amplifier (32, 33, 60, 67) have a first resonance circuit (34, 35) with a first bandpass characteristic for the selective amplification of the chrominance signal components contains that a bias circuit (22, 23, 42, 43) for setting a reference bias level determining a first gain state of the amplifier is coupled that the color sync signal amplifier coupled to the controllable amplifier (61) is connected to a second resonance circuit (98, 99, 120) with a second bandpass characteristic that the Detector circuit a peak detector (155, 156, 157) with an ÄC time constant element (156, 157) and that the coupling circuit (42) is the output of the peak detector with the bias circuit (22, 23, 42, 43) couples in such a way that the gain of the amplifier is set according to the change in amplitude of the oscillator signal. 6. Circuit according to one of the preceding claims, characterized in that the adjustable amplifiers (32, 33, 60, 67), the color sync signal amplifier (61), the oscillator (14) and the detector circuit (155) all in one monolithic integrated circuit chip are arranged. 7. A circuit according to claim 6, characterized in that the monolithic integrated circuit chip is provided on its edge with several connections (101 to 116) that the controllable amplifier has a first (32, 33), one second (60) and third (67) amplifier stages with DC coupling between the stages contains and that the first and the third amplifier.tufe a first and second to the first or second connection (116 or 114) have connected output that the burst signal amplifier (61) is connected directly to the second amplifier stage (60) and its output to a third connection (111), that the output of the oscillator (126, 127, 128) via the third connection (111) to the burst signal amplifier (61) and connected to the input to a fourth terminal (107) is that the detector circuit (155, 156, 157) with an input to the input of the Oscillator and with an output to an input of the first amplifier stage (32, 33) and with a second output is connected to a fifth connection (105) that a first, outside matched circle (34,35) provided on the circuit die with a first given Bandpass characteristic within the frequency range of the chrominance signal components at the first connection (116) is connected to the color type-selective amplification of the first stage, that a second tuned circle (72, 73) provided outside of the circuit board a second bandpass characteristic within said frequency range to the second connection (114) is connected to the color type-selective amplification of the third stage (67) that a third coordinated circle (98, 99, 120) provided outside of the circuit board a third given bandpass characteristic within said frequency range, the is wider than the first and the second bandpass characteristic, to the third terminal (111) selective amplification of the color sync signal is connected that the filter network (12) is provided outside the circuit board and a crystal (128) in series with a variable Contains capacitor (129), this series circuit being connected between the third and fourth terminals (111 and 107) is that the feedback voltage generated by the filter network is small compared to the Size of the supplied color sync signal is. ³ 4 in such a way that the amplitude of the oscillator signal accompanies almost every signal and can be caused by different causes known within the transmission range of the crystal, speaking of the signals at the third connection. The signals Uli; scmvankt, and that em outside of the sound are exposed to many different sources of interference. In the case of Λ ^ Ι iV ^ ^ ^or S " ^a time constant element 5 with a weak received signal strength, that in the receiver Uso, 1S7) from the parallel connection of a conger through the various input-level capacitors and a resistor to a five-generated thermal noise is of considerable concern Anscnluli (102) is connected, the time interpretation because with such a weak received signal constant is dimensioned in such a way that the size of the received signal with the carrier frequency has a peak rectifier effect io the size of the thermal noise generated in the receiver on the capacitor Voltage can be comparable. speaking of the variable-amplitude oscilloscope Usually circuits work for automatic generator signal arises. _{cal chrominance} control with a detector that has a 8. A circuit according to claim 7, characterized in that the voltage generated, which draws the mean amplitude of the, ς-β between the first (32,33) and the 15 contained in the signal mixture and second (60) amplifier stage for color transmissions, a DC-transmitted color sync signal is proportional. Coupling path with a long time constant provided on the circuit board by a mean value detector with relatively chen arranged avalanche diode (51), the arbitrary effects between the first connected to the first circuit (34, 3 *>) integrated out of the noise or interference matched out output 20 and one obtains an output voltage proportionate (116) and an input terminal of the second nismäßie is immune to noise and thus CARDINAL amplifier stage (61), on the wafer lent of "the amplitude of the color burst signal from ^is · depends. the selective reduction of the Chrominance signal 9. A circuit according to claim 1, characterized in these circuits by a suitable one shows that the coupling circuit (42) corrects the 25 AFR control circuit so that a desired more so that its gain for chrominance signal output levels is preserved in the receiver Low amplitude color information signals and remains. However, the glitches will be along with Interference components of high amplitude are essentially amplified in the chrominance signal, and that combined the borrowed output signal contained equal to the gain for Störkomponen- disturbances can always th low amplitude and color information - 30 nor the dynamic range of the chrominance channel, high amplitude signals. as it is done, for example, by the demodulators, 10. A circuit according to claim 9, marked switched chrominance intensifiers or the color picture tube net is given by one connected to the oscillator. Chrominance control circuits Arrangement (resistor 146) for changing the with a mean value detector supply a disturbance-peak-peak rest voltage amplitude of the output 35 independent output voltage level. Such gang signals as reference levels for the peak detection mean value detectors therefore ignore the fact gate circuit (155,156,157). that the actual dynamic range of the chrominance channel is exceeded. This can have the consequence that the color representation on the screen